Self-indicating mercury switch



March 19, 1940. A. w. BARBER 2,194,241

SELF-INDICA'I'ING MERCbRY SWITCH Filed Jan. 26, 1959 GaJJn Cbambery 01 444 1691 70 Glow Dif rer en! ('o/ora f0 Indiana/e Jun/06 Dani/ace! IN I 'EN TOR.

Patented Mar. 19, 1940 v UNITED STATES PATENT OFFICE 2.194.241 SELF-INDICATING MERCURY swrron Alfred W. Barber, Flushing, N. Y. Application January 26. 1939, Serial No. 252,897 21 Claims. (01. 200-452) My present invention concerns electrical switches and in particular illuminated mercury switches.

One object of my present invention is to provide an illuminated mercury switch. Particularly to provide self-contained illuminating means which glows blue or green when the switch is oil and red when the switch is on.

Another object is to provide an illuminated mercury switch in which closing the main circuit automatically and with the same pool of mercury changes the illumination from off to lon.!-I

j A further fobject is to provide a mercury switch in .which "off" is indicated when the switch is off and connected to a load.

A still further object is to improve visibility of the switch illumination thru the use of a,

transparent or translucent knob which concentrates the light and at the same'time serves as means for actuating the switch.

Another object is to provide either rotary or toggle movement in mercury switches with auto matic snap action.

Still another object is to provide one or more of the above objects in a switch element which may be easily replaced if it becomes broken or defective.

These and other objects .will be evident from the detailed description of my invention given in connection with the various figures of the drawing.

In the past, electrical switches have been made in which circuit contacts enclosed in an evacu ated case have been closed by a pool of mercury by tipping the switch case so that the mercury flows by gravity across the circuit contacts. I

have found that illumination of a mercury switch may be easily provided. An additional electrode is introduced into the mercury chamber connected thru:a current limiting resistor to the opposite side of the electrical circuit. By

admitting a small amount of air, mercury vapor v will exist which is ionized between the additional electrode and one of the circuit contacts providing a blue light for off which is extinguished by the mercury shorting the electrodes when the switch is turned to on."

' switch the circuit contact used to provide the In one form of my I have found that additional illumination may be provided. indicating when the switch is on by means of a second chamber. The second chamber is provided with electrodes for causing I illumination by ionization of a suitable gas.

While others may be used, I prefer to use neon positioned to act as a lens for the illumination inside the switch. Thus illuminating the switch .knob is very effective.

I have also found simple but eifective means for producinga snap action in a rotary switch. The circuit leads to the switch are made of flat 'or round spring material such. as 'phosphor bronze or steel and are held firmly on a terminal block. The switch body rotates on a pivot flex- 26 ing the spring leads in one direction when on" and the opposite direction when 011. In a modified form of my switch I use a toggle action "with a flat spring bearing against the switch body to provide snap action.

In the drawing: r Fig. 1 shows a section of one form of my mercury switch taken on line a of Fig. 2.

Fig. 2 shows an end view of the switch of Fig. 1.

Fig. 3 shows a section of a modified form. of my mercury switch taken on line b of Fig. 4.

Fig. 4 shows an end view 01' the switch of Fig. 3. Fig. 5 shows a section of a further modification of my switch taken on line d 01' Fig. 6.

Fig. 6 shows an end view 01' the switch. of Fig. 5.

Fig. 'I shows a section taken on line 0 of Fig. 5. Fig. 1 shows one form of my new mercury switch. It consists of a switch body I of glass or other suitable material, mercury chamber 3,

and additional illumination chamber 4. One end 65 of the switch body is formed into a projection 2 which serves as a grip for-operating the switch. In the other end of the mercury chamber the main circuit electrodes 1 and 8 project thru-the chamber wall and-are adapted to be bridged so across by the mercury pool 5 when the switch body is tilted at an angle of approximately degrees. The main circuit electrodes land 8' are connected in series with the main power leads I and I1, one or which goes to the power is source and the other of which goes to the load to be energized. Lead I8 forms the other circuit lead between the power source and the load. The mercury chamber contains an electrode 9 which is spaced from electrode 8 at a distance which will produce ionization of the gas in the chamber when connected across the line thru current limiting resistance 20. Chamber 3 is filled with a low pressure gas or air which is ionized to produce an indicating glow between electrodes 8 and 9. This glow indicates that the switch is in an oiP position and may be made to be green by the use of hydrogen or other desired colors by suitable gas choice. When the switch is tilted toan on position, the mercury takes up the position shown dotted at 6 and shorts out this off" illumination by shorting glow electrode 9 to circuit electrode 8. The lower part of the switch consists 'of a second chamber 4. In this chamber is an electrode l l extending into chamber 3 and electrode l2 connected to line I8 thru current limiting ,resistor l9. at low pressure if a red glow is desired or other suitable gas for other desired colors. Electrode II is connected to electrode 8 by mercury 5 when the switch is tilted. The voltage drop thus established across the gap between electrodes II and I2 ionizes the neon or other gas in chamber 4 producing a red or other colored glow indicating that the switch is on.

Fig. 2 shows a simplified end view of the switch of Fig. 1. Fig. 1 is a sectional view taken along line a of Fig. 2. Fig. 2 shows switch body I, mercury chamber 3, knob 2 and on" ionization chamber 4. This view also shows pins 2| and 2| which serve as pivots for the switch body. The switch is operated by tilting the switch body about these pivots by lifting on the projection or knob 2.

Fig. 3 shows a modification of my new mercury switch. It consists of a switch body 22 enclosing a mercury chamber 23, an ionization chamber 24 and a lens-knob 36. In the mercury chamber are mounted the main circuit electrodes 29 and 30 connected in circuit to source leads l6 and IT by means of spring connectors 33 and 34. An additional electrode 21 is provided which, with the extension 28 from main electrode 29, provides an ofi indication ionization gap. Electrode 21 is connected to supply lead l8 thru current limiting resistor 20 and spring connector 32. Spring connectors 32, 33 and 34 are held between the fixed terminal block 35 and the rotatable switch body 22. They are longer than a straight line between the two so that they flex as shown. When thus flexed they hold the switch against rotation. The switch is operated by rotating it around pivot 48 causing springs 32, 33 and 34 to flex in the opposite direction in a snap action which holds the switch in an on" position. Springs 32, 33 and 34 may be of phosphor bronze, steel 0r,other suitable spring material and may be flat, round or of any suitable cross-section.

The switch shown in Fig. 3 has a mercury chamber 23 containing the mercury pool 5, the

main circuit electrodes 29 and 39 and the off" glow electrodes 21 and 28. As shown in Fig. 4 the central part of the switch is formed into a lens-knob 36 which serves to rotate the switch body and as a light intensifier. Glow electrodes 21 and 28 are located behind the upper part of knob 38 so that the glow produced by them shines thru the knob. The knob is rounded to act as a lens and its outer surface may be roughened and/or fluted to further enhance the illumina- Chamber 4 is filled with neon gas a gas within said enclosure.

tion. Mercury chamber 23 may be filled with gas of proper composition to produce the desired color and intensity of glow at the normal switch operating voltage.

the lens knob. If it is desired to short out the "oft". glow electrodes 21 and 28, electrode 21 may pass lower in the neighborhood of electrode 29 and electrode 25 may be connected to lead It thru a second current limiting resistor.

Fig. 4 shows an end view 01. the switch oi Fig. 3 showing only the switch body 22, mercury chamber 23, mercury 5, lower ionization chamber 24, lens-knob 38 and pivot 48.

Fig. 5 shows a further modification of my new' mercury switch along a section at line d 01' Fig. 6. This form consists of a' body 40 01' glass or other suitable material enclosing a single mercury chamber 4| with mercury 5. An extension on the.

end forms a toggle operating means 45. Mercury chamber 4| also contains the main circuit electrodes u and u' (see Fig. '1), auxiliary indicating glow electrode 43 and a suitable ionizable gas at low pressure. Main circuit electrodes 44 and 44 are mountedin line thru opposite sides of chamber 40. Circuit connections to main electrodes 44 and 44' thru springs 38 and 38' secured to block 31 by means 01' screws 39 and 39'. The

I ends of springs 38 and 38' are cup-shaped to fit over the rounded outer ends of electrodes 44 and 44' and are formed to exert pressure enough to insure good electrical contact therewith. The auxiliary glow electrode 43 dips to a point near electrode 44 and is connected thru a suitable current limiting resistor 42 by means of lead 46 to spring 38 which contacts electrode 44". The gap between electrodes 43 and 44 ionizes due to the power line voltage only when a load is connected since there is no path to the opposite side of the line except thru the load. This blow may be extinguished by shorting with the mercury in the on" position as shown at 8 or it will go out due to shorting the main electrodessince it is connected in parallel with them. The switch is held in either an .ofl or an on" position by means of the flat spring 41 secured in block 31 at one end and pressing against the under side of body 40 at the other end. Fig. '7 is a section at line c oi. Fig. 5.

Fig. 6 shows an end view of the switch shown in detail in Figs. 5 and 7 showing only the switch body 49, mercury chamber 4|, mercury 5 and knob 45.

While I have shown and described only a few forms of my present invention'it will be apparent to those skilled in the art that many modifications and embodiments are possible within the spirit and scope of my invention asset forth in the appended claims.

What I claim is:

1. In an electric switch, an enclosure, a pair of contacts within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, and an additional contact for ionizing Iii) areaaar e 2. In an. electric switch, an enclosure, a pair of contacts within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, an additional contact for ionizing a gas within said enclosure, and a transparent switch operating means adjacent to said additional contact.

3. In an electric switch, an enclosure, a pair of'contacts within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, an additional contact adjacent to one of said contacts for ionizing a gas within said enclosure, and a transparent lens shaped switch operating means adjacent to said additional contact.

4. In an electric switch, a transparent enclosure, a pairof contacts .within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, an additional enclosure integral with said first enclosure, and a pair of contacts, within said additional enclosure for ionizing a gas within said additional enclosure.

5. In an electric switch, a transparent enclosure, a pair of contacts within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, an additional enclosure integral within said first enclosure, a pair of contacts within said additional enclosure for ionizing a gas within said additional enclosure, and transparent switch operating means adjacent to the last said pair of contacts.

6. In an electric switch, a transparent switch body embracing two enclosures, liquid circuit closing means within one of said enclosures, a pair of electrodes for ionizing a gas within said other enclosure,. and lens shaped light transmitting means adjacent to said electrodes.

7. In an indicating electric switch. a light transmitting enclosure, a pair of coaxial contacts within said enclosure, a liquid circuit closer with in said enclosure for bridging said contacts, a fiat spring substantially at right angles to the axis of said contacts for preventing accidental operation of said switch, and an additional contact for ionizing a gas within. said enclosure.

8. In' an indicating electric switch, a' light transmitting enclosure, a pair 01' coaxial contacts within said enclosure, a liquid circuit closer within said enclosure for bridging said contacts, and an additional contact for ionizing a gas within said enclosure.

9. In an'indicating electric switch, a transparent body embracing two enclosures, a pair of work contactswithin one of said enclosures, an additional contact bridging said two enclosures for ionizing a gas within the other of said enclosures, and a liquid circuit closer within the first of said enclosures for bridging said three contacts.

10. In an indicating electric switch, a transparent body embracing two enclosures, a pair of work contacts within one of said enclosures, an additional contact bridging said two enclosures for ionizing a gas within the other of said enclosures, a liquid circuit closer within the first 01 said enclosures for bridging said three contacts, and a lens shaped switch operating means adjacent to the ionization point of said additional contact.

11. In an indicating electric switch, a transparent body embracing two enclosures, a pair of work contacts within one of said enclosures, an electrode for ionizing a gas within said first enclosure, an electrode extending between said two enclosures, an additional electrode within the second of said enclosures for ionizing a gas within said second electrode. and a liquid circuit closer within the first of said enclosures for bridging said work contacts and at least one of said electrodes.

12. In an indicating electric switch, a transparent body embracing two enclosures, a pair of work contacts within one of said enclosures, a plurality of electrodes for ionizing a gas within each of said enclosures, and a liquid circuit closer within the first of said enclosures for bridging said work contacts and at least one of said electrodes.

13. In an indicating electric switch, a transparent body embracing two enclosures, a pair of work contacts within one of said enclosures, a plurality of electrodes for ionizing a gas within each of said enclosures, a liquid circuit closer within the first of said enclosures for bridging said work contacts and at least one of said electrodes, and light concentrating means adjacent to at least one of said electrodes.

14. In an indicating electric switch, a transparent body embracing two enclosures, a pair of work contacts within one of said enclosures, a plurality of electrodes for ionizing a gas within each of said enclosures, a liquid circuit closer within the first of said enclosures for bridging said work contacts and at least one of said electrodes, light concentrating means adjacent to at least one of said electrodes, and spring means for retaining said switch in either of two predetermined positions.

15. In an indicating electric switch, an enclosure including at least a light transmitting portion, a pair of contacts, a liquid circuit closer with in said enclosure, means within said enclosure for illuminating said light transmitting portion and a connection for energizing said illuminating means when said switch is in a predetermined position.

16. Ina two position indicating electric switch, an enclosure, a pair of contacts within said enclosure, a liquid circuit closer within said enclosure, light generating means within said enclosure, and a connection for energizing said light generating means at one of said switch positions.

17. In a two position indicating electric switch, an enclosure, a pair of contacts within said enclosure, a liquid circuit closer within said enclosure, light generating means within said enclosure, means for energizing said light generating means at one of said switch positions and means for deenergizing said light generating means at the other of said switch positions.

18. In a two position indicating electric switch, a transparent switch body embracing two enclosures, a pair of contacts within the first of said enclosures, a liquid circuit closer within said first enclosure, means for generating substantially red light within one of said enclosures, means for generating substantially green light within the other of said enclosures and means for energizing one of said light generating means when said switch is in one position and means for energizing 20. In an electric switch, a round switch body embracing two air tight enclosures, a pair of contacts and a liquid circuit closer with one of said enclosures, light generating means 'within the other of said enclosures energizable thru said circuit closenand light concentrating means adjacent to the last said enclosure.

21. In a. two position indicating electric switch, a transparent switch body embracing two enclot sures, a pair of contacts within the first of said enclosures, a liquid circuit closer within said first enclosure, means for generating a substantially red light within one of said enclosures, means'tor generating a substantially green light within the other of said enclosures, means for energizing one 0! said lightgenerating means at one of switch positions, and means for energizing the other 01! said light generating means at the other switch position.

ALFRED W. BARBER. 

